1. Field of the Invention
The present invention relates to embossed napkins. More particularly, the invention relates to napkins having a functional emboss design.
2. Description of the Related Art
Nearly all napkins, particularly multi-ply napkins, are embossed over some portion of the napkin's surface. A common functional reason to emboss multi-ply napkins is to bond individual plies together. This is usually accomplished with a coin edge emboss pattern, although other emboss patterns and ply-bonding techniques may also be used. Another common reason to emboss is to improve the attractiveness of the napkin to the consumer.
One of the long standing problems facing manufacturers of quality embossed napkins has been how to deliver to the consumer an attractive, undamaged, package of napkins that stacks and displays well on the store shelf. Many napkin packages are not rectilinear due to uneven bulk distribution in the individual napkins and, consequently, do not stack well on the shelf. Other napkins often buckle or pucker in the case during shipping and appear damaged, leading consumers to reject them.
To avoid these problems, some manufacturers have chosen to box their napkin products. However because boxes can add significantly to the expense of the napkins, most napkin stacks are generally simply overwrapped with polyethylene film. Various embossing and folding approaches have been developed to address the uneven bulk distribution and stackability problems of overwrapped napkin packages. However, it seems that many emboss patterns are chosen based more on aesthetics, with less attention paid to the effects the design may have on wrapping, shipping, and performance characteristics of the napkin products.
To produce tightly wrapped, square packages that stack well on the store shelf, it is important to achieve even or uniform napkin bulk. Package corners must be at substantially the same stack height for stackability. Uneven napkin bulk produces stacks that lean or tip over. Depending on the bulk distribution, uneven napkin bulk can also cause the product to buckle or pucker within the package.
A napkin package's resistance to puckering during handling, shipping, and storage, is, among other things, dependent on how tightly the wrapped package is packed into the case, the firmness of the wrapped package and the design of the emboss pattern.
Finally, the performance of the product in the hands of the consumer is key to the success of the product. The napkin must be attractive. The emboss design dictates how well the individual plies hold together and the availability of smooth, unembossed areas for wiping comfort. The design and folded format of the napkin also determine whether the napkin can be refolded in a variety of ways.
Three main embossing approaches are currently in practice and involve embossing: only the edge; the entire napkin; or the edge along with other selected spots. Each approach is reviewed below.
The first approach produces a napkin that has only an edge emboss. The emboss patterns applied to most of the area of an edge and extending fully to the edge in substantially complete coverage of the area adjacent the edge are usually termed "coin edge embosses." The advantages of this approach are that it is possible to get good ply-bonding and it leaves a large, smooth surface for wiping the face and hands. The napkin bulk and consequently the napkin stack, however, is uneven so this design leads to a wrapped product that is vulnerable to puckering. Furthermore, because of uneven bulk, the wrapped napkin package has at least one low corner which in turn can cause stacks of the packages to tip over, or individual packages to slide off each other. This defect becomes more pronounced as the stack height of the package increases.
The second approach embosses the entire napkin surface area. The advantage of an overall emboss is that uniform stack bulk is achieved, which promotes good packaging and shelf performance. Ply-bonding tends to be poor, however, because it is difficult to attain the high pressures needed in the emboss nip with the increased emboss area. In addition, the entire napkin surface is embossed leaving no smooth unembossed area for wiping, thus detracting from both the softness and attractiveness of the napkin.
Spot embossing, the third approach, embosses other spots of the napkin along with the traditional embossed edge. This approach generally involves the placement of various sized emboss elements to increase the attractiveness of the folded napkin. The advantages of this approach fall between the extremes of the two previous approaches in that the bulk of the napkin stack can start to approximate that of the overall emboss approach while still preserving some of the ply-bonding characteristics of the coin edge embossed only approach.
Similarly, the disadvantages are a combination of the above two approaches. Lumpy or uneven bulk can lead to product puckering and poor stacking. In addition, too many elements detract from the attractiveness of the napkin, decrease the smooth area available for wiping, and may lower the strength of the ply-bonding. The comparative advantages and disadvantages of the napkin of the present invention and the napkins described above are summarized in Example 1 below.
The napkins described above are most commonly quarter folded, i.e., folded in half twice to form another but smaller nearly square napkin. In some cases, however, napkins produced by any of the above approaches are eighth folded, instead of the more traditional quarter fold. This format may be used for consumer convenience or for manufacturing convenience as the eighth fold can further level out the bulk profile. An eighth fold napkin format, however, does not permit the consumer to refold the napkin in alternative ways without the residual eighth fold being apparent. For example, consumers often prefer a triangular or diamond fold in the napkin when it is placed on the table top. These designs are easily produced from quarter-fold napkins by folding along diagonals. However with an eighth-fold napkin, the last fold generally spoils the aesthetics of the design.
In light of the foregoing, there is an immediate need for a napkin which eliminates or reduces puckering, provides better resistance to puckering during shipping and handling, and has engineered pucker points to reduce the severity of the degradation in appearance caused by puckering. In addition, a napkin is desired that has uniform stack bulk to produce a quality overwrapped package that is a right-angled parallelepiped that stacks well on the store shelf, has good ply-bonding, a large unembossed smooth wiping area, is attractive, and allows the consumer maximum folding flexibility.